Production of cyclo-olefinic hydrocarbons and aromatic hydrocarbons



Patented Aug. 27, 1946 PRODUCTION OF CYCLO-OLEFINIC "HYDRO- CABBONS AND .AROMATIC @HYDROCAR- BONS Herman Pines and Vladimir-"N. Ipatiefi, Chicago,

111., assignors to Universal Oil Products Company, Chicago, 111., a corporation of Delaware .No Drawing. Applica'tionDecember15,.1944,

Seri'a'l'No. 568,392

, 1 f'l'his invention relates to a process for producing cyclic hydrocarbons. More specifipally, the invention relates .to a process for producing cycloolefins by condensing a diolefinic Thydrocarbon having at least 4 carbon atoms'per molecule with amonohydric alcohol.

An object of this 'i'nvention'is the condensation of a monohydric alcohol with a conjugated di- 'olefinic hydrocarbon containing :at least i carbon atomsper molecule.

Another object of this invention i the production of a cyclohexene/hydrocarbon by con densing analkanol with a'oonjugated diolefin.

A further-object of this invention is the production of a cyclohexene hydrocarbon by the condensation of a conjugated diolefin with an alcohol selected from the group consisting of primary and secondary alkanols.

A still further object of this invention is the production of 1,3,5-trimethylcyclohexene by condensing 2-methyl-1,3-pentacliene and isopropyl alcohol.

One specific embodiment of this invention relates to a process for producing a cyclo-olefin which comprises condensing an alkanol and a diolefinic hydrocarbon having, at least 4 carbon atoms perv molecule in the presence of an acidacting catalyst at a temperature of from about 150 to about 400 C.

A further embodiment of this invention relates to a process for producing a benzene hydrocarbon which comprise condensing an alkanol and aconjugated diolefin to produce a cyclohexene hydrocarbon, hydrogenating said cyclohexene hydrocarbon to a cyclohexane hydrocarbon, dehydrogenating said cyclohexane hydrocarbon to a benzene hydrocarbon and hydrogen, and utilizing at least a portion of said hydrogen in the hydrogenation of said cyclohexene hydrocarbon.

cyclohexene and difierent alkyl cyclohexene hydrocarbons which are obtainable by the process of our invention may be hydrogenated to cyclohexane hydrocarbons or they may be dehydrogenated to benzene and alkyl benzene hydrocarbons.

By the term condensation used inthis specification and in the claims, we mean the chemical combination of a diolefinic hydrocarbon having at least 4 carbon atoms per molecule and a monohydric alcohol accompanied by the splitting out of water. Thus, 2-methyl-1,3-pentadiene and isopropyl alcohol react at an elevated temperature and preferably in the presence of an acidacting catalyst to produce 1,3,5-trimethylcyclohexene and water as the principal products of the process.

2 Diolefin'ic hydrocarbons utilizable in our process contain at least :4 carbon atoms per molecule and are preferably conjugated diolefins inthat each of said hydrocarbons contains a'system' of alternate single and double bonds including .two double bonds. Althoughthe reaction of ourprocessiproceeds preferably with conjugated diolefins, other diolefins are sometimes usable, particularly when rearrangement occurs at the conditions of the reaction.

, Monohydric alcohols utilizable also as starting materials in the process "of our invention "are generally those of the;aliphatic-seriesand -preferably aresaturatedaliphatic carbinols which are also known as alkanols. Alkanols which do not contain a quaternary carbon atom are particularly desirable for condensation with a diolefinic hydrocarbon as herein set forth as alkanols which contain a quaternary carbon atom sometimes yield a substantial proportion of a tertiary olefin rather than the condensation product desired.

Although our process issometimes carried out in the absence of an added catalyst at suitable operating conditions of temperature and pressure, we prefer to utilize certain catalytic materials to assist in the condensation of a diolefinic hydrocarbon and a monohydric alcohol. Catalysts so utilizable are acid-acting materials and comprise activated alumina, hydrated silica, acidtreated clays; synthetically prepared composites including silica-alumina, silica-alumina-zirconia, alumina-zirconia, silica-alumina-thoria, etc.;. acids such as hydrochloric acid, hydrobromic acid, a phosphoric acid, sulfuric acid, or a heteropoly acid as phosphotungstic or phosphomolybdic acid; and also aqueous solutions of hydrolyzable salts such as ferric chloride, magnesium chloride, zinc chloride, ammonium chloride, magnesium acid phosphate, sodium acid sulfate, etc. These materials which we employ as catalysts in our process are acid-acting in the sense that an aqueous solution or suspension thereof in water has a pH .below 7.

of our invention, although the example is not introduced with the intention of restricting unduly the broad scope of the invention.

1.6 molecular proportions of isopropyl alcohol and l molecularr proportion =of; Z-methyl-lfis pentadiene are commlngled and charged to an autoclave containing a by weight solution of The volume of the ammonium chloride solution is about thatof' the mixture of a diolefinic hydrocarbon-and isoammonium chloride in Water.

propyl alcohol introduced thereto. After the autoclave and contents are heated atabout 250 C. for 3 hours, the heating is discontinued and V the reaction mixture is permitted to 'cool.,,.After cooling, the reaction mixture, contains an 113- drocarbon layer comprising 1,3,5-trimethylcyclo-=I'- hexene in an amount corresponding toabout 35% of the theoretical yield based upon the di-,

olefin charged. JI'lie novelty and utility of theprocess of the molecule and a monohy'dric alcohol at a sufficient temperature and pressure that condensation of said diolefim'c hydrocarbon and monohydric alcohol i the principal reaction of theprocess.

ZJA process jorproducing a cyclo-olefinic hy- 4 drocarbon which comprises condensing a diolefinic hydrocarbon having at least 4 carbon atoms per molecule with an alkanol at a temperature of from about150 to abouti400f C I v 3. A process for produc ng a; cyclo olefinic hydrocarbon which comprises condensing a diole- -finic hydrocarbon having at least 4 carbon atoms per molecule with an alkanol at a temperature of from about 150 to about 400 C. and at a pressure of from about 1 to about atmospheres.

4. A process for producing a cyclo-olefinic hydrocarbon which comprises condensing a diolefinic hydrocarbon having at least 4 carbon atoms per molecule with an alkanol in the presence of an acid-acting catalyst at a temperature of from about to about 400 C.

5. Aiprocess for producing a cyclo-olefinic hydrocarbon which comprises condensing a diolefinic hydrocarbon having at least 4 carbon atoms per molecule with an alkanol'in the presence of an acid-acting catalyst at a temperature of from about 150 to about 400 C. and at a pressure of from about 1 to about 100 atmospheres.

6. A process for producing a cyclo-olefinic hydrocarbon which comprises condensing a conjugated diolefinic hydrocarbon with an alkanol in the presence of an aqueous solution of a hydrolyzable metal salt at a temperature of fromabout 150 to about 400 C. and at a pressure of from about 1 to aboutlOO atmospheres.

' HERMAN PINES.

VLADIMIR N. IPA'I'IEFF. 

